December 15, 2019 by Luke James
DSL (Digital Subscriber Line) technology provides consumers high-speed internet connection (up to 8 Mbps), significantly higher than traditional modems with data speed of up to 56 Kbps.
Although DSL technology is developed using DSP (Digital Signal Processing) algorithms and data coding schemes, it requires operational amplifiers.
Due to its low power consumption, effective noise cancellation and other characteristics, a differential amplifier is used as a line driver/receiver in DSL systems. Microchip Technology Inc, a leading provider of analog, connectivity and power management semiconductors, has specifically designed the Le87536 Dual Channel Differential Amplifier to drive full-rate ADSL2+ signals with minimal power dissipation.
Le87536 Dual Channel Line Driver. Image Credit: Microchip.
The Le87536 integrates two sets of high-power line driver amplifiers designed with Zarlink’s HV30 Bipolar SOI process, that can be connected for full duplex differential line transmission. They are designed to be used with signals up to 10 MHz with low signal distortion. The amplifiers have an internal fixed gain, which helps to eliminate external feedback and gain setting resistors.
The Le87536 Dual Channel Differential Amplifier features improved frequency compensation for all applications, allowing stable operation at very low power levels, eliminating the need for an external “snubber” circuit. Differential circuits, such as ADSL (Asymmetric DSL) line driver applications, can be especially prone to common-mode oscillation. The Le87536 is specifically designed to eliminate this type of instability and guarantees reliable operation even at very low power levels.
An ADSL2+ Modem. Image Credit: TP-Link.
Due to its low power consumption, the Le87536 Dual Channel Differential Amplifier can be used as a high-performance and cost-effective line driver in ADSL and ADSL2+ systems. In a typical ADSL/ADSL2+ application, a differential line driver is used to take the signal from the analog front end (AFE) and drive it onto the twisted pair telephone line. ADSL2+ or G.992.5 is an ITU-T (ITU Telecommunication Standardization Sector) standard for ADSL broadband Internet access.
Given below is a comparison between Microchip’s Le87536 Dual Channel Differential amplifier and similar amplifiers designed by Analog Devices and Texas Instruments.
With its low power consumption, high output current, high output voltage swing and fixed voltage gain, Le87536 Dual Channel Differential Amplifier is an ideal line driver for ADSL, HDSL (High-bit-rate DSL) and other xDSL systems.
